This Center differs from the usual General Clinical Research Center in that it is not associated with a general hospital or a medical school. The usual categorical departments - medicine, surgery, pediatrics, etc. - do not exist. Rather, there are several independent laboratory groups participating in the Center, each with its own area of interest in problems of human biology or pathology. The clinical research is primarily in the form of long-term studies of pathogenesis of selected disease processes, and each group has extensive laboratory facilities for basic research correlated with the clinical research. The major areas of current research include: endocrine effects on skeletal growth and maturation of bone; metabolism of lipids in relation to arteriosclerosis; addictive disorders; obesity; endocrine pharmacology, including studies of porphyria and lead poisoning; sickle cell anemia; immunological disorders, visceral learning; and rheumatic fever. In each case, the studies are directed toward better understanding and/or control of the processes involved. Most of the training in the Center is at the postdoctoral level. In addition to full-time postdoctoral fellows, residents from New York Hospital have been participating for 6-month periods under a cooperative program.